1. Field of the Invention
This invention relates to an Entry Alert Guard that provides an audible message whenever an entryway is opened or left unsecured.
2. Description of the Related Art
Swimming pool gate alarms have the potential for saving the lives of hundreds of children who die every year because of accidental drowning. Many of these drownings occur when children gain entrance to pool areas through unsecured pool gates. These drownings could be averted if an effective warning system were available to ensure the proper closure of swimming pool gates. The gate alarms currently available have several design deficiencies that prevent these alarms from being truly effective. The most significant of these deficiencies is the alarm system's reliance on their obnoxious noise level to signal an open entryway.
Intentional vandalism is a common occurrence and usually prevents pool gate alarms from effectively performing their life saving role. The gate alarm's noise tends to attract juveniles who frequently vandalize and render these alarms inoperable. In addition to juvenile vandalism, these units are often the target of adults who disable the unit merely to stop the intensely irritating noise that they produce.
This alarm noise problem also manifests itself in another operational problem. In an emergency, the alarm noise tends to create additional confusion. This confusion comes not just from the mental stress created by the intense noise, but also from the concurrent inability to communicate with others. Consequently, the alarm may actually hinder a favorable outcome to the situation.
Another problem with the current state of the art is that these alarms are often battery powered. Battery life is dependent on the usage of the device, the number of alarms, and even the weather conditions. Consequently, the battery will fail unexpectedly. Without back up power, the alarm is immediately disabled, and will remain so until maintenance detects the dead battery.
Instead of battery power, many industrial and commercial applications use alarms that require 120-volt AC power. These power sources may not be practical because of the remoteness of the installation to readily available power outlets. In addition, the high voltage levels required by such systems may present a safety hazard. In particular, these alarms present an unacceptable high safety risk when used around pool enclosures where the presence of water could produce an electrical shock hazard.
Ko (U.S. Pat. No. 5,473,310) presents the most significant example of prior art in swimming pool gate alarms. This patent discloses a pool guard alarm that uses a gate sensor, (including a magnetic sensor and a permanent magnet), a battery power source, a delay timer, and a reset button. Holding a gate open after a predetermined time delay will cause the alarm to sound. In addition, failing to push the reset button after entry will also cause the alarm to sound.
The Ko patent, however, has some severe shortcomings. First, the Ko patent relies on a battery that will drain and fail at some unpredictable time, defeating the alarm's safety purpose. Secondly, the alarm mechanism is located on the gate itself and is subject to tampering or vandalism that can defeat the device. Thirdly, the device only sounds an obnoxiously loud alarm. This often only instills within people a desire to disable the alarm. Fourth, the alarm does not identify why it is sounding. Fifth, the alarm does not provide instructions for the alarm's termination.
U.S. Pat. No. 4,278,968 (Arnett) discloses a prior art device that provides an audible alarm when a door is not properly closed. Using magnetic switches in conjunction with a time delay relay, an alarm automatically sounds if the door is left open for a period longer than the pre-set time delay. The circuit automatically resets itself once the entryway is closed. This device has severe design deficiencies when utilized as a swimming pool gate alarm. The alarm's use of a 120 V-power supply presents a safety hazard. Although the 120-volt supply power is transformed to a lower operating voltage, that portion of the circuit at the higher operating voltage still presents a safety hazard. A failure in the high voltage circuit could propagate and present a safety hazard on even the low voltage circuit. Because of current rectification, this prior art design requires more components of greater complexity. These additional components increase maintenance and reliability problems. Finally, the device when activated can only produce a blaring alarm, the shortcomings of which have already been noted above.